Merge pull request #171 from jama5262/ISSUE-170_work_on_diff_implemen…

…tation [ISSUE-170] Move the diff implemetation to a new file
jama5262 · Dec 29, 2022 · 04c0489 · 04c0489
2 parents d608fd4 + 34c5b9f
commit 04c0489
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Showing 6 changed files with 436 additions and 74 deletions.
diff --git a/lib/src/display.dart b/lib/src/display.dart
@@ -1,9 +1,16 @@
 import 'package:intl/intl.dart';
 
+import 'getter.dart';
 import 'enums/units.dart';
+import 'manipulator.dart';
 import 'utils/exception.dart';
 
 class Display {
+  final Getter getter;
+  final Manipulator manipulator;
+
+  Display(this.getter, this.manipulator);
+
   String formatToISO8601(DateTime dateTime) => dateTime.toIso8601String();
 
   String format(DateTime dateTime, String pattern, String ordinal) {
@@ -20,9 +27,48 @@ class Display {
     return '';
   }
 
-  num diff(DateTime firstDateTime, DateTime secondsDateTime, Units units,
+  num diff(DateTime firstDateTime, DateTime secondDateTime, Units unit,
       bool asFloat) {
-    return 0;
+    final firstDateTimeMicrosecondsSinceEpoch =
+        getter.microsecondsSinceEpoch(firstDateTime);
+    final secondDateTimeMicrosecondsSinceEpoch =
+        getter.microsecondsSinceEpoch(secondDateTime);
+    final diffMicrosecondsSinceEpoch = firstDateTimeMicrosecondsSinceEpoch -
+        secondDateTimeMicrosecondsSinceEpoch;
+
+    var diff;
+
+    switch (unit) {
+      case Units.MICROSECOND:
+        diff = diffMicrosecondsSinceEpoch;
+        break;
+      case Units.MILLISECOND:
+        diff = diffMicrosecondsSinceEpoch / Duration.microsecondsPerMillisecond;
+        break;
+      case Units.SECOND:
+        diff = diffMicrosecondsSinceEpoch / Duration.microsecondsPerSecond;
+        break;
+      case Units.MINUTE:
+        diff = diffMicrosecondsSinceEpoch / Duration.microsecondsPerMinute;
+        break;
+      case Units.HOUR:
+        diff = diffMicrosecondsSinceEpoch / Duration.microsecondsPerHour;
+        break;
+      case Units.DAY:
+        diff = diffMicrosecondsSinceEpoch / Duration.microsecondsPerDay;
+        break;
+      case Units.WEEK:
+        diff = (diffMicrosecondsSinceEpoch / Duration.microsecondsPerDay) / 7;
+        break;
+      case Units.MONTH:
+        diff = _monthDiff(firstDateTime, secondDateTime);
+        break;
+      case Units.YEAR:
+        diff = _monthDiff(firstDateTime, secondDateTime) / 12;
+        break;
+    }
+
+    return asFloat ? _absFloor(diff) : diff;
   }
 
   String _replaceEscapePattern(String input) {
@@ -41,9 +87,59 @@ class Display {
     return pattern;
   }
 
-  // tod understand what this regex pattern does
+  // todo understand what this regex pattern does
   Pattern _matchesOrdinalDatePattern() {
     return RegExp(
         '''(?<unquote>[^"'\\s]\\w*)|(?:["][^"]+?["])|(?:['][^']+?['])''');
   }
+
+  num _monthDiff(DateTime firstDateTime, DateTime secondDateTime) {
+    if (getter.date(firstDateTime) < getter.date(secondDateTime)) {
+      return -(_monthDiff(secondDateTime, firstDateTime));
+    }
+
+    final monthDiff =
+        ((getter.year(secondDateTime) - getter.year(firstDateTime)) * 12) +
+            (getter.month(secondDateTime) - getter.month(firstDateTime));
+
+    final thirdDateTime = _addMonths(firstDateTime, monthDiff);
+    final thirdDateTimeMicrosecondsSinceEpoch =
+        getMicrosecondsSinceEpoch(thirdDateTime);
+
+    final diffMicrosecondsSinceEpoch =
+        getMicrosecondsSinceEpoch(secondDateTime) -
+            thirdDateTimeMicrosecondsSinceEpoch;
+
+    var offset;
+
+    if (diffMicrosecondsSinceEpoch < 0) {
+      final fifthDateTime = _addMonths(firstDateTime, monthDiff - 1);
+      offset = diffMicrosecondsSinceEpoch /
+          (thirdDateTimeMicrosecondsSinceEpoch -
+              getMicrosecondsSinceEpoch(fifthDateTime));
+    } else {
+      final fifthDateTime = _addMonths(firstDateTime, monthDiff + 1);
+      offset = diffMicrosecondsSinceEpoch /
+          (getMicrosecondsSinceEpoch(fifthDateTime) -
+              thirdDateTimeMicrosecondsSinceEpoch);
+    }
+
+    return -(monthDiff + offset);
+  }
+
+  int _absFloor(num number) {
+    if (number < 0) {
+      return number.ceil();
+    } else {
+      return number.floor();
+    }
+  }
+
+  DateTime _addMonths(DateTime dateTime, int months) {
+    return manipulator.add(dateTime, 0, 0, 0, 0, 0, 0, 0, months, 0);
+  }
+
+  int getMicrosecondsSinceEpoch(DateTime dateTime) {
+    return getter.microsecondsSinceEpoch(dateTime);
+  }
 }
diff --git a/lib/src/getter.dart b/lib/src/getter.dart
@@ -56,7 +56,7 @@ class Getter {
     return int.parse(DateFormat('Q').format(dateTime));
   }
 
-  // todo see if you can use a parse and formatter class
+  // todo see if you can use a formatter class
   int dayOfYear(DateTime dateTime) {
     return int.parse(DateFormat('D').format(dateTime));
   }

diff --git a/lib/src/manipulator.dart b/lib/src/manipulator.dart
@@ -71,50 +71,61 @@ class Manipulator {
     switch (unit) {
       case Units.MICROSECOND:
         newDateTime = DateTime(
-            dateTime.year,
-            dateTime.month,
-            dateTime.day,
-            dateTime.hour,
-            dateTime.minute,
-            dateTime.second,
-            dateTime.millisecond,
-            dateTime.microsecond);
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime),
+            getter.second(dateTime),
+            getter.millisecond(dateTime),
+            getter.microsecond(dateTime));
         break;
       case Units.MILLISECOND:
         newDateTime = DateTime(
-            dateTime.year,
-            dateTime.month,
-            dateTime.day,
-            dateTime.hour,
-            dateTime.minute,
-            dateTime.second,
-            dateTime.millisecond);
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime),
+            getter.second(dateTime),
+            getter.millisecond(dateTime));
         break;
       case Units.SECOND:
-        newDateTime = DateTime(dateTime.year, dateTime.month, dateTime.day,
-            dateTime.hour, dateTime.minute, dateTime.second);
+        newDateTime = DateTime(
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime),
+            getter.second(dateTime));
         break;
       case Units.MINUTE:
-        newDateTime = DateTime(dateTime.year, dateTime.month, dateTime.day,
-            dateTime.hour, dateTime.minute);
+        newDateTime = DateTime(
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime));
         break;
       case Units.HOUR:
-        newDateTime = DateTime(
-            dateTime.year, dateTime.month, dateTime.day, dateTime.hour);
+        newDateTime = DateTime(getter.year(dateTime), getter.month(dateTime),
+            getter.date(dateTime), getter.hour(dateTime));
         break;
       case Units.DAY:
-        newDateTime = DateTime(dateTime.year, dateTime.month, dateTime.day);
+        newDateTime = DateTime(getter.year(dateTime), getter.month(dateTime),
+            getter.date(dateTime));
         break;
       case Units.WEEK:
         var newDate = subtractDuration(dateTime,
             Duration(days: getter.dayOfWeek(dateTime, startOfWeek) - 1));
-        newDateTime = DateTime(newDate.year, newDate.month, newDate.day);
+        newDateTime = DateTime(
+            getter.year(newDate), getter.month(newDate), getter.date(newDate));
         break;
       case Units.MONTH:
-        newDateTime = DateTime(dateTime.year, dateTime.month);
+        newDateTime = DateTime(getter.year(dateTime), getter.month(dateTime));
         break;
       case Units.YEAR:
-        newDateTime = DateTime(dateTime.year);
+        newDateTime = DateTime(getter.year(dateTime));
         break;
     }
     return newDateTime;
@@ -125,61 +136,77 @@ class Manipulator {
     switch (unit) {
       case Units.MICROSECOND:
         newDateTime = DateTime(
-            dateTime.year,
-            dateTime.month,
-            dateTime.day,
-            dateTime.hour,
-            dateTime.minute,
-            dateTime.second,
-            dateTime.millisecond,
-            dateTime.microsecond);
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime),
+            getter.second(dateTime),
+            getter.millisecond(dateTime),
+            getter.microsecond(dateTime));
         break;
       case Units.MILLISECOND:
         newDateTime = DateTime(
-            dateTime.year,
-            dateTime.month,
-            dateTime.day,
-            dateTime.hour,
-            dateTime.minute,
-            dateTime.second,
-            dateTime.millisecond,
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime),
+            getter.second(dateTime),
+            getter.millisecond(dateTime),
             999);
         break;
       case Units.SECOND:
-        newDateTime = DateTime(dateTime.year, dateTime.month, dateTime.day,
-            dateTime.hour, dateTime.minute, dateTime.second, 999, 999);
+        newDateTime = DateTime(
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime),
+            getter.second(dateTime),
+            999,
+            999);
         break;
       case Units.MINUTE:
-        newDateTime = DateTime(dateTime.year, dateTime.month, dateTime.day,
-            dateTime.hour, dateTime.minute, 59, 999, 999);
+        newDateTime = DateTime(
+            getter.year(dateTime),
+            getter.month(dateTime),
+            getter.date(dateTime),
+            getter.hour(dateTime),
+            getter.minute(dateTime),
+            59,
+            999,
+            999);
         break;
       case Units.HOUR:
-        newDateTime = DateTime(dateTime.year, dateTime.month, dateTime.day,
-            dateTime.hour, 59, 59, 999, 999);
+        newDateTime = DateTime(getter.year(dateTime), getter.month(dateTime),
+            getter.date(dateTime), getter.hour(dateTime), 59, 59, 999, 999);
         break;
       case Units.DAY:
-        newDateTime = DateTime(
-            dateTime.year, dateTime.month, dateTime.day, 23, 59, 59, 999, 999);
+        newDateTime = DateTime(getter.year(dateTime), getter.month(dateTime),
+            getter.date(dateTime), 23, 59, 59, 999, 999);
         break;
       case Units.WEEK:
         var newDate = addDuration(
             dateTime,
             Duration(
                 days: DateTime.daysPerWeek -
                     getter.dayOfWeek(dateTime, startOfWeek)));
-        newDateTime = DateTime(
-            newDate.year, newDate.month, newDate.day, 23, 59, 59, 999, 999);
+        newDateTime = DateTime(getter.year(newDate), getter.month(newDate),
+            getter.date(newDate), 23, 59, 59, 999, 999);
         break;
       case Units.MONTH:
-        var endMonthDate = Getter.daysInMonthArray[dateTime.month];
-        if (Query.isLeapYear(dateTime.year) && dateTime.month == 2) {
+        var endMonthDate = Getter.daysInMonthArray[getter.month(dateTime)];
+        if (Query.isLeapYear(getter.year(dateTime)) &&
+            getter.month(dateTime) == 2) {
           endMonthDate = 29;
         }
-        newDateTime = DateTime(
-            dateTime.year, dateTime.month, endMonthDate, 23, 59, 59, 999, 999);
+        newDateTime = DateTime(getter.year(dateTime), getter.month(dateTime),
+            endMonthDate, 23, 59, 59, 999, 999);
         break;
       case Units.YEAR:
-        newDateTime = DateTime(dateTime.year, 12, 31, 23, 59, 59, 999, 999);
+        newDateTime =
+            DateTime(getter.year(dateTime), 12, 31, 23, 59, 59, 999, 999);
         break;
     }
     return newDateTime;
@@ -191,15 +218,22 @@ class Manipulator {
 
   DateTime _addMonths(DateTime dateTime, int months) {
     final modMonths = months % 12;
-    var newYear = dateTime.year + ((months - modMonths) ~/ 12);
-    var newMonth = dateTime.month + modMonths;
+    var newYear = getter.year(dateTime) + ((months - modMonths) ~/ 12);
+    var newMonth = getter.month(dateTime) + modMonths;
     if (newMonth > 12) {
       newYear++;
       newMonth -= 12;
     }
-    final newDay =
-        min(dateTime.day, getter.daysInMonth(DateTime(newYear, newMonth)));
-    return DateTime(newYear, newMonth, newDay, dateTime.hour, dateTime.minute,
-        dateTime.second, dateTime.millisecond, dateTime.microsecond);
+    final newDay = min(
+        getter.date(dateTime), getter.daysInMonth(DateTime(newYear, newMonth)));
+    return DateTime(
+        newYear,
+        newMonth,
+        newDay,
+        getter.hour(dateTime),
+        getter.minute(dateTime),
+        getter.second(dateTime),
+        getter.millisecond(dateTime),
+        getter.microsecond(dateTime));
   }
 }
diff --git a/lib/src/parser.dart b/lib/src/parser.dart
@@ -1,9 +1,14 @@
 import 'package:intl/intl.dart';
 
 import 'enums/units.dart';
+import 'getter.dart';
 import 'utils/exception.dart';
 
 class Parser {
+  final Getter getter;
+
+  Parser(this.getter);
+
   DateTime fromString(String input, String? pattern, List<String> ordinals) {
     if (pattern != null) {
       if (pattern.trim().isEmpty) {
@@ -49,14 +54,14 @@ class Parser {
       throw JiffyException('The provided datetime map cannot be empty');
     }
     return DateTime(
-        input[Units.YEAR] ?? DateTime.now().year,
-        input[Units.MONTH] ?? DateTime.now().month,
-        input[Units.DAY] ?? DateTime.now().day,
-        input[Units.HOUR] ?? DateTime.now().hour,
-        input[Units.MINUTE] ?? DateTime.now().minute,
-        input[Units.SECOND] ?? DateTime.now().second,
-        input[Units.MILLISECOND] ?? DateTime.now().millisecond,
-        input[Units.MICROSECOND] ?? DateTime.now().microsecond);
+        input[Units.YEAR] ?? getter.year(DateTime.now()),
+        input[Units.MONTH] ?? getter.month(DateTime.now()),
+        input[Units.DAY] ?? getter.date(DateTime.now()),
+        input[Units.HOUR] ?? getter.hour(DateTime.now()),
+        input[Units.MINUTE] ?? getter.minute(DateTime.now()),
+        input[Units.SECOND] ?? getter.second(DateTime.now()),
+        input[Units.MILLISECOND] ?? getter.millisecond(DateTime.now()),
+        input[Units.MICROSECOND] ?? getter.microsecond(DateTime.now()));
   }
 
   DateTime parseString(String input, String pattern) {